In recent years, from the standpoint of protection of global environment, there has been increasing interest in energy saving, and a power management system such as HEMS (HOME ENERGY MANAGEMENT SYSTEM) that manages power per house has attracted attention (e.g., see Patent Literature 1). Patent Literature 1 discloses that when a measured current value does not decrease to a predetermined current before elapse of a predetermined time after exceeding a preset warning reference quantity, power supply to predetermined load devices is individually cut, thereby preventing power supply to all the load devices from being cut simultaneously by a current limiter or a breaker due to overuse of electricity.